[ltp] lower CPU clock without battery in X61s
Mon, 30 Jun 2008 08:57:17 +0200
On Thu, Jun 26, 2008 at 07:51:36 +0200, Tino Keitel wrote:
> On Thu, Jun 26, 2008 at 07:34:40 +0200, Yves-Alexis Perez wrote:
> > On mer, 2008-06-25 at 20:44 +0200, Tino Keitel wrote:
> > > my X61s only uses 1,2 GHz if I remove the battery, even with the
> > > performance cpufreq governor. With the battery inserted, it uses 1,6
> > > GHz. Is there something I can do to get the maximum CPU clock even
> > > with
> > > the battery removed?
> > Yes, this is known, and supposedly it's to protect the thinkpad. It may
> > be a feature of EIST (Enhanced Speedstep) but I couldn't find any spec
> > on this on the net.
> The funny thing is that it is not always the case. I just had the
> chance to use the full CPU clock without the battery inserted.
This way I get the full CPU speed without the battery inserted:
1. boot with the battery inserted and AC connected
2. suspend to disk
3. remove AC power
4. remove the battery
5. plug in AC power
6. resume from suspend
I don't know if there is a more simple way, though.